This section addresses three key aspects. The first part focusses on Lean techniques; the second explores the role of technology in Lean implementation; and the third examines their application within the project engineering sector. While Lean principles have been extensively studied and applied within the manufacturing industry, there is limited research on their direct implementation in the engineering projects sector.
The background provided here will outline the benefits of Lean in its traditional manufacturing context, exploring how these principles, when combined with modern technological advancements, can be adapted to enhance value in engineering projects. Firstly, a description of Lean in its purpose-developed environment, the manufacturing industry, is provided. This is followed by examining how these concepts can be extended to engineering projects. This foundational understanding then sets the stage for developing the subsequent conceptual model.
2.1. Lean Techniques
The manufacturing industry has adopted Lean tools and is known for showing improved productivity [
6]. Countries such as China have proven competitive advantages [
7]. Implementing Lean methods has demonstrated positive effects and has been shown to make processes more optimised and efficient, enhancing an organisation’s overall productivity and profitability [
8]. The idea behind Lean implementation in an organisation is to allow continuous opportunities for long-term development [
9]. The Lean tools are seen to be successfully implemented in the manufacturing and maintenance environment [
10].
Lean principles are widely used worldwide, and it has been found that many benefits are associated with implementing the Lean concept [
10]. The industry must profit through the implementation of the Lean technique system. The system should not be limited to manufacturing but should benefit all sectors. The Lean idea is adaptable to any industry and should be used in all sectors to reap the benefits. There are various Lean techniques, all of which show benefits in their own way [
11]. It is emphasised that to experience the full benefit of Lean principles, organisations must accept the new approach to working and thinking [
12]. Research has indicated that organisations confront obstacles in conducting constant improvement initiatives to enhance production efficiency [
13].
Many organisations implement Lean techniques to see continuous improvement, greatly benefiting a business [
14]. It is still evident that several barriers are affecting the implementation of Lean techniques [
12]. Research conducted in the manufacturing industry demonstrates the effectiveness of Lean transformation on organisational structure and behaviour. It also highlights Lean methodologies’ efficacy and sheds light on the elements that influence transformation and implementation [
15]. The elements of an effective Lean structure are illustrated in
Figure 1 below [
15].
Organisations fail in the successful implementation of Lean techniques because companies are only engaged in the physical characteristics of Lean, which include Lean methods and principles [
14]. A positive mindset and vision are also needed to implement Lean tools [
2]. Additionally, top management teams must work to inspire staff members to uphold a continuous improvement and Lean principal culture [
16]. Elements, such as the knowledge of key individuals and a lack of desire to make an innovative change, contribute to the difficulties encountered in applying Lean methodologies [
17]. A company shift is required to apply Lean concepts because business culture plays a pivotal role in implementing Lean techniques [
12]. With a fundamental change that has a significant impact, it is expected there will be strong resistance [
12]. The behaviour of leaders plays a vital part in any organisational change [
18]. Among the barriers affecting the implementation of Lean techniques is the buy-in from employees and management [
12]. Other factors that impact change are reluctance to make a change, low motivation levels of personnel, limited company goals, and poor conceptualisation of Lean tools [
17]. At the same time, it is also emphasised that there is a need for training and knowledge transfer on Lean techniques before implementing them [
11]. For Lean tools to be successfully implemented and show improvement in an organisation, it is necessary to incorporate the related human element that drives the Lean technique approach [
6]. Businesses often find it problematic to establish a connection between adopting Lean methods and gains in operations [
19]. The perception towards change plays a vital role in adopting Lean tools [
11]. An organisation’s success relies on its employees and performance [
20]. Even though Lean manufacturing is widely acknowledged to enhance operations, many organisations are having trouble adjusting to the Lean mindset [
20].
Lean principles have been extensively studied and adopted in various global industries, yet South Africa’s adoption of these techniques has been relatively slow [
21]. According to Donodofema et al. (2017), South Africa faces significant challenges in fully embracing Lean methodologies, which are already well integrated in countries like Germany [
21]. The study highlights that despite having over 50 years of experience with Lean concepts, South Africa has not capitalised on this knowledge effectively. One of the critical gaps identified is the assumption by some South African companies that simply implementing Lean techniques makes them Lean. However, this overlooks the comprehensive nature of Lean, which requires more than just implementation. It demands a cultural shift and continuous improvement, deeply embedded within the organisation [
21]. Furthermore, the study underscores the importance of human resources in driving continuous improvement, a core component of Lean. Continuous improvement, as highlighted, is not just a process but a culture that must be cultivated within the workforce. The failure to fully integrate these principles has prevented South African companies from realising the full benefits of Lean, such as increased efficiency, reduced waste, and enhanced competitiveness [
21]. To bridge this gap, there is a need for targeted investment in Lean research and development, ensuring that Lean practices are implemented and sustained through continuous learning and improvement [
21]. By addressing these gaps, South African industries, particularly in the engineering projects sector, can better align with global standards and leverage Lean methodologies to improve project outcomes. This is especially relevant in adopting new digital technologies, which can facilitate the implementation of Lean by streamlining processes and enhancing real-time decision-making [
21]. Integrating Lean with digital technologies could be a significant step forward in achieving operational excellence in the South African engineering projects sector.
2.2. Technology and Lean Implementation
The increasing use of automation technologies in Lean manufacturing emphasises the need for a new phase of production system transformation [
22]. This is enabled by Industry 4.0 technologies and aims to digitise production, improving industrial processes and systems. This allows quick adjustments in production methods to meet changing requirements, using innovative technology based on Industry 4.0 and Lean management principles [
22]. Furthermore, looking at the construction project environment, Lean construction principles should be combined with digitalisation to improve efficiency and productivity in ongoing investment projects, commonly known as Lean 4.0 [
23]. This combination enables a realistic strategy to increase worker productivity and project effectiveness [
23]. However, before integrating digital technology into a Lean approach, it is recommended that the traditional physical Lean methodology be established [
24]. This approach helps develop a culture of reflection and forward-thinking, setting the groundwork for innovation and preparing for digitalisation [
24]. At the same time, it is worth noting that integrating Lean and Industry 4.0 poses challenges such as reduced flexibility, higher costs, and a limited ability to make changes during construction using Lean concepts.
The integration of modern technology has become indispensable across various disciplines, offering significant benefits in the engineering projects sector. Adopting new technologies extends to all sectors, providing crucial support for continuous improvement, an essential component of successfully implementing Lean methodologies [
25]. The Industrial Revolution introduced groundbreaking ideas, concepts, and technologies, fundamentally transforming work processes [
25]. Today, the implementation of strategies that facilitate ongoing improvement, in tandem with technological advancements, is vital for maintaining a competitive edge [
25]. Also, the application of modern technology has proven to be beneficial in a variety of disciplines. The adoption of new technologies and the benefits thereof extend to all sectors [
25].
In the context of Lean principles, new technologies complement and enhance Lean techniques, offering substantial benefits when integrated with appropriate processes [
11,
26]. Deploying multiple Lean tools alongside technology can streamline an organisation’s operations, optimising system performance and operational efficiency. This symbiotic relationship underscores the importance of selecting the right technology, continuously improving its application, and staying abreast of technological advancements [
27]. Implementing new technology creates opportunities to provide new solutions [
28]. For example, Kriel (2020) discusses how technology can reduce labour requirements while simultaneously improving operational efficiency, which presents challenges and opportunities depending on the perspective [
25]. Furthermore, it is understood that implementing digitalisation might lessen or eliminate present and upcoming difficulties in operational systems [
27]. Effective management systems are critical to maximising the benefits of technology implementation. Organisations must recognise the significant advantages of adopting cutting-edge technology, ensuring that these innovations are aligned with Lean methodologies to achieve superior financial management and resource allocation [
28]. The rapid adoption of new technologies in industries like packaging production demonstrates how technological advancements can create new opportunities and improve efficiency [
28]. According to a case study conducted in the South African biomedical sector, technological improvement is a key strategy for process improvement, which extends beyond immediate operational gains to encompass broader organisational benefits [
29].
Innovative technologies such as automation, AI, robotics, blockchain, and the Internet of Things are revolutionising the manufacturing sector [
26]. These advancements facilitate better planning, scheduling, and execution of tasks with minimal disruptions, ensuring compliance with regulations and reducing the likelihood of human errors [
26,
30]. Mechanisation decreases the number of workers who engage with machines, decreasing the probability of human being mistakes and facilitating the speedier fulfilment of production objectives [
30]. Studies show that digitalisation in asset management reduces or eliminates current and future challenges in system management [
27], with research indicating that it leads to more effective system monitoring and problem resolution [
11]. Innovative technology would allow for effective planning, scheduling, and execution of planned maintenance on time and with few disturbances, maintaining regulatory compliance [
26]. Technology transfer is pivotal in maximising the benefits of technology adoption, particularly in emerging economies. According to Owusu-Manu et al. (2017), technology transfer fosters social infrastructure development and economic growth, as seen in Ghana’s construction sector, where multinational companies serve as key innovation and technological improvement sources [
31]. However, the success of technology transfer depends on regular evaluation and the effective transfer of knowledge and skills to local populations [
31]. The need for ongoing assessment ensures that Indigenous people can acquire new knowledge and skills without difficulty, supporting the long-term benefits of technology implementation [
31].
2.3. Lean Implementation in the Projects Sector
Implementing Lean techniques, particularly within the construction project environment, is an advanced approach to managing projects in this sector [
10]. The benefits of implementing Lean techniques are evident, and it is widely recommended that these methods be adapted across various project sectors [
7]. Evidence suggests that the South African construction project industry is actively exploring various Lean techniques, processes, and practices [
10]. There are numerous Lean techniques, each with its own approach and method of implementation. These strategies will be applied differently in different project environments. It is important to note that while Lean concepts were originally established for the manufacturing sector, careful adaptation to suit the specific conditions of any other industry or project environment should lead to successful outcomes. The Lean approach involves different techniques, each contributing a unique perspective to a system or process. When implemented correctly, many benefits can be realised. The selection of a Lean tool depends on the specific project process and should involve matching the most appropriate tool to the given project needs [
9]. Several Lean tools are available, and deploying one or more incorrectly can have negative impacts and add little value. Research indicates that the construction project sector is increasingly adopting Lean techniques [
9]. Although Lean methods have only recently been adopted in project-focused construction environments, they were long associated with the manufacturing sector. In the South African construction space, Lean techniques are being applied to projects, with tools such as 5S and Kaizen identified to address issues like defects, overprocessing, waiting times, and underutilised staff skills [
9]. A study on Lean audits has identified certain Lean features as standard across projects, including standardised work, housekeeping, swift changeover methods, total productive maintenance, and continuous improvement [
19]. Moreover, it is emphasised that a mindset focused on continuous improvement is a critical component of the Lean philosophy within project management [
19].
Over time, various strategies have been employed to enhance effectiveness and quality in the construction project sector [
10]. Implementing Lean principles in construction projects aims to achieve task execution at a reduced cost, ensure client satisfaction, and minimise waste [
10]. The prioritisation of safety and quality is vital for project execution and must be emphasised throughout the project lifecycle [
2]. Research shows that SMEs in the construction project sector face numerous challenges [
2]. Among these challenges are production inefficiencies, poor quality, overspending, and significant waste [
2]. It is also important to recognise that Lean techniques are not a quick fix for problems; their benefits are only realised gradually over time [
9]. However, consistent implementation of Lean techniques in projects is expected to lead to benefits such as financial improvement, quality enhancement, disciplined employees, and a highly skilled workforce [
21]. In the context of construction SMEs, it is found that it is often best to implement tools requiring less cash investment [
2]. However, the effectiveness of these strategies depends on a business structure that emphasises soft factors such as regard for people, shared values, transparency, trust, and teamwork [
32]. Additionally, a study on sustainability in projects highlights that successfully integrating sustainable development dimensions at various phases of the construction project lifecycle requires a combination of project management competencies, including organising, leading, planning, and technical knowledge [
33]. Furthermore, it has been established that the success and development of Lean methods in the projects industry, specifically construction projects, highlights the need to address barriers to broader adoption [
34]. The key obstacles impacting the success and development of Lean methods, as identified by Al Balky et al. (2021), are as follows: lack of top management support, inadequate worker training, limited awareness of Lean principles, ineffective communication of necessary information, and insufficient stakeholder involvement and transparency [
34].
Research in the structural design sector highlights the issue of waste and demonstrates how Lean practices can reduce this waste, bringing value to project outcomes [
35]. The design process in engineering projects, particularly during the pilot and detailed design stages, often generates waste, negatively affecting project success [
36]. Effective management strategies are essential to mitigate waste in the design phase, as they directly impact the overall efficiency and quality of project execution [
36]. The design stage typically involves compiling client requirements, developing technical drawings, evaluating these drawings for compliance, and executing the approved designs in the field [
36]. Addressing waste at each stage is critical for enhancing project performance and ensuring the successful delivery of engineering projects [
35,
36]. The broader project sector in South Africa, including engineering and construction projects, involves substantial annual investments [
10]. However, the sector still lags behind the manufacturing industry in adopting Lean techniques [
10]. Given the significant financial stakes, funds must be allocated and utilised systematically to avoid waste and maximise the potential benefits of Lean methodologies [
10]. Implementing Lean principles across projects is crucial for reducing waste and improving overall operational efficiency and project performance [
2,
10]. The systematic application of these principles can lead to more efficient use of resources, better alignment of project goals with client expectations, and reduced unnecessary expenditures, all of which are vital for successful project outcomes [
2]. Lean principles in the project sector aim to enhance productivity, reduce execution time, and improve safety and quality throughout the project lifecycle [
2]. These benefits are particularly important in sectors where project timelines are critical and client satisfaction is paramount [
2,
37]. Moreover, Lean techniques minimise waste and optimise resource utilisation, which are key factors in achieving project success [
37]. While these principles offer significant advantages, it is essential to recognise that their benefits are realised gradually and require consistent application over time [
9]. This approach is especially relevant for SMEs within the project sector, which often face challenges such as production inefficiencies, poor quality, overspending, and waste [
2,
9]. Addressing these issues through Lean methodologies can lead to significant operational improvements and long-term success [
9]. Moreover, research has shown that Lean techniques positively impact reducing waste, improving quality, and increasing value for money across various projects [
37]. It is often emphasised that the successful implementation of Lean principles requires the simultaneous application of multiple Lean tools, tailored to the specific needs of each project [
21]. This multifaceted approach allows organisations to address their unique challenges, ultimately leading to better financial performance, higher-quality outputs, and more disciplined and skilled teams [
21]. The benefits of Lean techniques are not confined to any single industry; they are applicable across various sectors, including engineering projects, where the focus is on enhancing efficiency and reducing waste throughout the project lifecycle [
21,
29]. By addressing common issues such as excess working capital tied up in stock and the need for rework, Lean methodologies help organisations streamline their operations, reduce costs, and improve overall project outcomes [
29]. It has been shown that small and medium-sized firms (SMEs) play a key role in an economy [
7]. Throughout a project’s life cycle, various methods and processes are executed at different stages, each requiring separate management systems to ensure successful project outcomes [
10]. Projects, particularly in the engineering and construction sectors, are unique and complex, often executed on-site, distinguishing them from the manufacturing sector [
10]. This distinction necessitates a different approach to implementing Lean techniques originally developed for manufacturing [
10]. Despite these challenges, it has been demonstrated that Lean tools can be effectively integrated into the project cycle, yielding significant benefits.
In recent years, the project sector has adapted Lean manufacturing tools to be more flexible, leading to the evolution of the term “Lean construction” [
32]. Lean construction is a project delivery approach that focusses on meeting customer needs while simultaneously reducing waste [
32]. Elements of the Lean construction culture, such as ensuring dependable workflow, fostering teamwork, respecting individuals, and enhancing transparency, were inherent in traditional construction practices [
32]. However, it has been observed that while Lean approaches are utilised in project environments, they are not always formally adopted. Collaboration, standardisation, and sustainability are critical to implementing Lean principles within project sectors. Lean construction emphasises creating a collaborative environment, standardising products and processes to make projects more efficient, and ensuring sustainability, particularly in waste reduction and social and environmental responsibility [
32]. Internationally, the sustainability of construction and engineering projects poses a significant challenge, impacting various stakeholders, including developers, designers, and city planners [
38]. Proper project planning is essential to address these challenges, and sectors like construction must explore multiple avenues to improve project efficiency and outcomes [
39]. Research indicates that a Lean engineering strategy can save space and address issues like excessive waste generated during project execution [
39]. Applying Lean techniques minimises waste and reduces the negative environmental impact of projects. For instance, a case study in the building construction sector found that clients’ requests for more space are often met, but the space is not always optimised, leading to increased costs [
39]. Government authorities also play a crucial role in promoting sustainable project practices, and collaboration with the private sector is encouraged to implement Lean techniques effectively [
38]. Studies on Lean methodologies across various African countries highlight the mixed readiness of construction companies to adopt these practices. For example, research on Nigerian construction firms shows that while there is process readiness, there are significant gaps in technology, people, and management, indicating an overall unpreparedness for Lean construction [
40]. The study emphasises the need for training and awareness, suggesting that tertiary institutions should offer programs related to Lean techniques [
40]. Despite the challenges, the construction industry remains a major source of employment globally, though persistent issues continue to affect the sector [
40]. While Lean techniques were initially developed for manufacturing, research shows they have been successfully applied in various project sectors. The adoption approach may vary depending on the industry and the specific organisation, but the benefits of Lean methodologies have been significant across multiple sectors. There is also evidence that some sectors implement Lean concepts indirectly without formally recognising them as such. The advantages of Lean principles, well-documented in manufacturing, have been shown to offer substantial value to other industries. However, adoption rates remain relatively low outside of manufacturing on a global scale.